Stay strip



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' KM fKwm" ATTORNE 4 J. GOLDMAN April 6, 1943.

STAY STRIP Filed Aug. 2, 1940 Patented Apr. 6, 1943 FF-lvca STAY STRIP n vJoseph Goldman, New Brunswick, NJ., assigner,

bymeanealaigmnen ration of South Caro U Application August 2, 1940. Serial No. 349,505

ts,toSanteeMiils lina iz claim. (Cl. zza-49)y This invention relates to stay strips. This invention relates particularly to stay strips suitable for reinforcing boxes, cartons and the like.

Heretofore the stay strips that have been in general use have had as a base material a wovenl fabric which may be illled with a suitable filler such as clay and a binder and which may be adhesively united to a paper sheet. On one side of the stay strip a water activatable adhesive such as glue has been used'. The woven cloth for a stay strip is sleazy, curls and raveis and there-,- fore must be reinforced by the addition of paper or by nlling the interstices with clays and sizing material. The filler or paper or both also has the functionof preventing the glue upon activation with water from striking throughthe stay strip and rendering the opposite side thereof sticky and adhesive. Moreover, in a woven cloth a large part of the cotton content is used for warp threadsto bind the filling threads and since the warp threads do not perform any substantial strain resisting function the warp threads constitute a waste of uber.

It is a purpose of this invention to improve upon prior art stay strips and materials therefor and to a'ord a more economical and better method of manufacturing stay strips and stay strip material.` j

According to this invention instead of using a woven fabric as a strain resisting base material, theV strength and toughness necessary for stay strips and material therefor is provided by unspun long fibers disposed in the direction of the nbers, preferably cotton nbers over about inch in length, are initially made up in the form of thin striated webs having a preponderant fiber direction. Preferably the nbers in the webs are substantially straight and are arranged approximately in one direction.

strain and integrally bonded in sheet material of substantial weight and thickness.

Bome of the features of this invention relate lto the disposition and orientation of the unspun iibers-in the stay strip and stay strip material. Other features relate to the fabrication of the stay strip and stay strip material from a plurality of web materials and the character of said web materials and dispositionv of said web materials in a resulting composite sheet of stay strip material and in the ilnished stay strip.

Other features of this invention relate to the character and disposition of the binder material for bonding the ilbers and the webs in an integral sheet and the character and disposition of thel adhesive used'in securing the stay strip to an article.

Inpreferred practice of this invention unspun long fibers are disposed and oriented so as to achieve in the finished product high strength characteristics for resisting the strains to which stay strips are subjected in use. To this end the In my application Serial Number 349,311 nied August 1, 1940, for Fibrous structural material and method and apparatus for making sameLlI have described the manufacture lof integrally bonded unspun brous webs which are characterized by the fact that fibers contained therein are arranged so as to have a preponderant fiber direction and so that at least .a maior proportion will be straight. Such web material, preferablyl when a high proportion of fibers isarranged approximately in one direction and is of substantially tensioned straightness, namely the straightf ness that the fibers assume when subjected to tension, may be used in the practice of this invention. It is not the intention, however, necessarily to limit the character of the web material 'that may be used in the fabrication of stay strips and stay stripV material to web material made as shown and described in my said application a1- though the use of such web material is to be preferred. The fibers in a web material that is used in the practice of this invention should, however, be arranged so as to have a predominant fiber direction by some suitable treatmentsuch as drafting, combing or the like.

Unspun fibrous web material in which long fibers are oriented as above described is used in fabricating laminated composite sheet material. the web material preferably being plied in superposed juxtaposition; and by the disposition of the web materialdesired characteristics can be achieved in the resulting composite sheet and stay strip made therefrom. For example, in certain embodiments of this invention superposed laminations of fibrous web material are disposed so that as to a major proportion of the webs of long fiber thev preponderant ilber direction lies transverse ofthe stay strip and preferably lies at a small angle with respect to the transverse dimension of the stay strip, e. g. be

' tween about 3 and about i5' of the transverse struction very hi gh capacity to resist tensile strains is anorded transversely of the stay strip distribution of the tensile load over substantially the adhesive all of the individual fibers disposed in the limitedangular position mentioned so that great strength V- resistant to the strain is afforded. By dispos-"Y ing all or a maior proportionY of the webs so A further advantage of this invention is that a stay strip is afforded that in preferred embodiments isadapted to'become adhesive-ly bonded to the surface of an article by a material, which,

If the 5 unlike ordinary glue for Aexample is not softened Iby moisture or dampness. It has been a serious de fect of stay strips used at the present time that when a box or carton on which a stay strip if this type is used becomes exposed to dampness is softened and the stay strip comes on. Moreover, according to this inventionV a stay strip canl be Amanufactured which is substantially waterproof and prevents moisture or dampness from penetrating through the stay that the preponderant direction of the i'ibers is 15 strip.

transverse of the stay strip 'within a limited angular disposition of the order mentioned exceedingly high resistance to shocks and tensile 4strains across the stay strip can be achieved. At

-the same time capacity to yield in the opposite 2 .direction without rupture can be afforded.

other .features of vthis-invention roiatelto the straightness of the unspun fibers in individual webs and the extent to which the fibers are `brought to one direction thereby securin'g'maxi- 25 mum strength characteristics in component web material fused in making stay strip and gstaystrip The foregoing as thisl inventionwill be* described more in detail hereinbelow in connection with the drawing.

coherent. integral laminated sheet' material by' i lmeansl of a suitable binder. While any. binder Y Unspun nbrous web material is bonded. into material appropriate' for use as a binder for Vilbei's 'may be used. in'preferred practice av thermoplastic binder is which is resistant in water, that is, which doesnot' excessivelyfr` rapidly dissolve, soften or deteriorate when subjected to water, dampness, or excessive humidity. t.

' Preferably such a binder is impregnated substanintimate association with each other. Moreoven a thermoplastic adhesive material adapted tobe tially throughout thestay strip material so that theviibers and the webs are strongly bonded inl 1 -activated by heat'to impart stickiness thereto isv preferably carried on,- orr at the surface ofthe r stoy strip so that merely upon noot activation oii f the .lsminations exaggerated for the purpose oi. 1 the adhesive materialI the stay strip canbe 5 0. clarity. and j '1 f bonded to'the surface of an article. Fig. 9Sisaplan view of'an additional modified weight strips wheny aillxedy cartons.-

. v in the'stay strip material. The new product isi also non-ravelling.

and has veryhigli resistance to strains in the direction that strains are applied to stay which stay strips tend to tear ext'ensively especially afterv any break is once started The new stay strip is 'also advantageous "inf asmuch as it can be manuiacturedwithout utilizl ing the relatively costly operation of spinning and of'weaving ing operation can likewise be eliminated when a binder is used that is also adapted to adhesively y' stay activation to impart superficial stickiness to the Awell vas additional vcontrolled l toartlcles, e. g.; boxes and The new product is much superior this respect tofstay strips composed-of fabrics filled with clay nllers and binders'and coated *with glue',

formed intoathin-web threads. A separate glue-apply,'=

- Number 349,311 nled August 1, 1940, referred to Further purposes, features and advantages of this invention will become apparent'in connection with thefollowing description of certain illustrative embodiments of this invention' in thereof,

shown in Fig. 1 on a somewhat enlarged scale.

Fig. 3 isgajtransverse sectional'view of-the stay stripmaterial shown in Fig. i on' a greatly aber structures that illustratothe practico of 3o enlarged scale taken on the liney of Fis. 1.

Fig. 4 is a longitudinal sectional view'of afrag-l `xnent of. the stay strip materiall shown in Fig. l' on the same greatly 'enlarged scale of Fig. 3 takenon the line H .of Fig. j i 4 Fig. 5 is. av longitudinal side elevational view of x a modified form of stay strip material embo'dying l larged'sca'le of Fig, 3;. v

F18. 6 is a pe Fig.7

layers, Fis. a. is

form ofstay'strip-,material embodying this iii-v show the fiber structure.

ple the fiber-used in the manufacture ofthe stay is over 1 inchl in length. I'he cotton is first by repeatedly, drafting and. lapping the cotton after it has been vcarded Iuntil about '10%' ofthe nbers 1 inch or more in -lengthhas been arranged approximately in one ample, as described in my\ application Serial above, and as described in my application the fibers in the drafted web material are preferably bonded together while the web is under tension .in the preponderant direction of the fibers so Fig. 2 is o longitudinal side oievstionoifview or the completed portion of the stay strip material thisA invention on. thesame somewhat enf s tive viewofa-staystripxem." 4o bodying this'in ention, thethickness ofthe stay -strip being shown on an enlarged scale for oler- 'I is a-plan view ofaii additionalembodiff v ment of lthis invention ,with this 'upper layersv f 5. broken awayl to show nber-1disposition in :lower sectional.u vievv'l ofthe `stay strip shown in Fig"...8'with the-thickness-of v'e'nti'onv with successive layers broken away to lfRieferring to the drawing and particularly-'to Figs. -1 toc onestructurally-'simple and inert-v pensively-manufsctured embodiment of this inf f vention will be described for purposes of exenipliilcation. In order to afford a specific exam-v strip; is cotton iioorA at roost about '10%.- oi which direction and is "drown to substantial axial raightness. This may be accomplished, .forfexy strip and pressing the stay strip against the .a

surface of an alude, that the .fibers in that direction may be bonded VWhen the laminations are angle to each other, as inthe embodiment shown,

are shown to indicate Athe composite sheet. i The stay strip material is impregnated with a.

-in a general way together while in a condition of tensioned straightness.' The web material preferably weighs about 100 to 250 grains per square yard.

The web material conditioned as above described is then fabricated by a plaiting operation into a laminated composite sheet as shown in Figs. 1 to 4. For example, a composite sheet may be formed that is about 40 inches wide by continuously plaiting an elongated lconditioned web material about 16 inches wide back and forth on itself with a zigzag motion so that there will be about 9 transverse travels about 40 inches long for each yard of resulting composite sheet thereby producing a composite sheet having about 4 thicknesses or laminations of the original web at any one point. Inl order to minimize any tendency of the selvages to wrinkle, the material being deposited and the material already deposited may be turned relatively. to each other at each change of direction so that the material will be laid down straight in each passage across the deposited material,

In Fig. 1 the conditioned web Il is shown being I l laid in plaitings or laminations ita and IIb whichv are also indicated on an enlarged scale in Figs. 2, 3 and 4, to form the composite sheet which is indicated generally bythe reference character Il. It may be noted that the preponderant ilber direction of all of the laminations ila is in one direction and that the preponderant fiber direction of all of laminations ilb is in anvother direction 'at a small angle. e. g., about 10 to the ber direction of laminations lia and that thefiber direction of none of' the laminations is directly across the transverse dimension of-the axis of tn e sheet i 1. Ihe laminations ila and .35 Asheet", i. e. at a right angle tothe longitudinal ith are superposedv in juxtaposition.. The number of ylaminations Ila in this embodiment are the same as the-number of laminations ilb.

it is preferable that the number of laminations in cned'irection be same as the number of in the web laminations be. less than about 30 to each other and less than about 15 to' theV v transverse dimension'of the material.

The drawing is not a scale drawing but has `certain aspects exaggerated for purposes of clarand 4 more than 4 laminations the laminated nature of ity. In Figli, 3

suitable. binder adapted to bond both the nbers and the fibrous webs together as an vintegral sheet. `1"or the purpose of affording a speciilc example, the binder may be a bituminous binder preferably having a softening point, ring and ball,

of 140 to 175 F. Preferf' with the bistrip materialV so that preferably about 20% to' 30% is incorporated,` the by speckling in Figs. 3 made to show the adhesive being indicated and 4. adhesive by speckli-ng except disposed at a small' binder may alsov be on the smaller scale jilguresat least approximately the i laminations in the other direction. It is preferable that fiber -direction No attempt is 1 such as Fig. 1, although it -is to be understoodj the heat liquefied bitumen. If desired in order to obtain a thorough penetration of the sheet without incorporating. an excess of. bitumen therein, the bitumen may bethinned with a volatile solvent or sion. Preferably web material before the web material is deposited in laminations as described in my application, Serial Number 349,311 filed August 1, 1940, inasmuch as byv so doing the `distribution ofthe binder throughout the composite sheet of staystrip material can be made more uniform, and the fibers can be bonded'in the elemental webs in a condition of tensioned straightness. Moreover, it is also possible to bond the fibers of-the elemental web material at the time that the web material is manufactured, e. 1 or 2% of a binder so that the fibers which have been straightened may be bonded in a'straightf ened condition as described in my ysaid application and then apply the balance of the bonding material when the elemental web materia is made up into stay strip material.

After the staystrip material has been formed and the binder has been incorporated therein, it can be cut into stay strips, the dotted lines il indicated in Fig. 1. Portions of stay strips i0 are shown inl Fig. i. that have been cut free and in Fig..6 a stay strip that has been cut from sheet I1 is ness thereof on an enlarged scale to indicate the disposition of the ilbers.: .A suitable adhesive carried at the surface of the stay strip is indicated by the speckling in Fig. 6. A e

The stay strip manufactured as above de, scribed can be reinforce boxes, cartons or the used .for any purpose. e. g., to

advantage is taken of the fact that the stay strip is impregnated with a thermoplastic material that is activatable by sticky when applying the stay face ofan article. Merely by strip to the surso asf-to cause at least the strip can be caused to adhere to`an article. This can be readily. done as by passing the stay'strip .over aV heated roller and then pressing the stay stripagainst the surface of the article before the vheat-activated binder hardens. Upncooling to lnormal atmospheric temperature the stay strip article. If it is desired remains adhered to the v a superficial coating 2l of thermoplastic binder can be applied to the surface of the stay strip material either before or after it is cut into stay strips so as to insure the presence of sufficient thermoplastic binder carried at or adjacent the surface lto obtainagood bond with the surface Iof any article lto which the stay 'strip may be applied.` 'I'he thermoplastic material in 'coating Il may be of alower softening point than the thermoplastic material used inv the lbody of the stay strip, e. g. about F. to about 140 1". In this manner the softening of the adhesive can be facilitated and the danger of excessively` softening the thermoplastic-binder in the bodyv of the stay strip is minimized. If desired the dispersed in an aqueous emulthe binderis applied to the' g., by using about e. g.. by cutting along shown, withthe thicklike. Preferably .I

heat to `become heating the stayv strip immediately before application to an article surface that is to' -be subjected to moisture or be passed over a flame instead of over a heated4 roller to quickly heat the surface portion of the stay strip and render it sticky before the stay strip is applied to an article.

A stay strip constructed as above described has exceedingly high strength transversely. Inasmuch as stay strip for cartons and boxes is subjected for the the stay strip constructed as above decribed has much greater resistance to such strains per unit weight than do stay strips of the character heretofore used. Moreover, due tothe small angularity. of the 'disposition of the conditioned webs there is a slight giving action against transverse strains which is immediately followed by an unyielding resistance, thus increasing the resistance of the stay strip to sudden transverse shocks without undue stretching. In order to promote this effect it is preferable to employ binder material such as bituminous material of relatively low softening point, latex or the like which can "give slightly without crumbling. Moreover, due to the angularity of -the disposition of the conditioned webs, the stay strip has some strength longitudinally coupled with the capacity to stretch longitudinally without rupture. By the structure mentioned above a stay strip is provided which has great strength in resisting the type of strains to which stay strips'are subjected in the most common uses thereof coupled with certain yielding capacity particularly longitudinally that minimizes the danger of rupture. It may also be addedthat since the stay strip is impregnated with a bituminous binder, the

stay strip is resistant to penetration by moisture.v

't is of even greater practical importance that the stay strip can be affixed adhesively to the surface of an article by an adhesive that is not adversely affected by moisture. Notwithstanding that a box or carton to which a stay strip of the character described has been attached may dampness, the stay strip remains securely afilxed thereto.

In Fig. 5 amodltied form of this invention is shown in which the composite sheet of stay strip material comprises a main body portion 2l that may be identical with the stay strip material I1 shown in Figs. 1 to 4 and described hereinabove. Integral therewith is another portion 22 which may comprise one or more laminations ofA conditioned web materialln which amai or proportion of the fibers are approximately straight and are disposed approximately in one direction longitudinally of the web material and of the composite sheet of stay strip material. In the drawing two such laminations 22a and 22h of web material are shown for purposes oi* exampliilcation. A binder material such as a material. The structure shown in Fig. 5 has greater resistance to longitudinal strains and less capacity to yield longitudinally than does the embodiment shown in Figs. 1 to 4.

The somewhat different embodiment of this invention is shown in Figs. 'I and 8 wherein elemental striated web material is disposed with the predominant fiber direction of the-bulk oi the web transversely of the stay strip material. The

top lamination is composed of striated websv 23A most part to transverse strains` butuminous binder im. pregnates the entire composite sheet of stay strip posed of webs 2l.

martiaux vthe preponderant fiber direction thereof at an angle of about 10 to the cross dimension oi' the sheet of stay strip material as a whole. Similar striated webs 2l are disposed with the preponderant i'iber direction thereof at an opposite like angle to the cross dimension of the sheet as a whole in a lamination of form thickness underlying the lamination com- Striated webs 23 are disposed similarly to webs 2l in a third lamination and webs 2l fourth lamination. If desired a fifth lamination may be made of striated webs 21 extendinglongitudinally of the vstay strip material with the edges of the web The cobondlng of the fibers in the individual webs and the bonding of the webs into an integral laminated sheet of stay strip material may be accomplished in the manner described above in connection with the embodiments of this invention shown in Figs. 1 to 5. Theblnder is indicated by the speckling. An adhesive material can be applied to a surface of the stay strip material as above mentioned. Preferably the web elements are disposed in the different laminations so that theabutting edges do not directly overlie abutting edges of elemental webs invother laminations, particularly withV regard to those laminations wherein the fiber direction is substantially the same. Thus a stagger arrangement such as shownv in Figs. 'l and 8 is preferable. Alternatively the elemental web materia' in the different laminations can be deposited in ribbons of somewhat different width in the difi'erv ent laminations so as to accomplish this `pur- As aforesaid the lamination of webs 21 can be omitted if desired. Somewhat more generally the number of laminations of web material in which the fiber direction is either transverse of the stay strip material or longitudinally thereof can be varied as desired.

In Fig. 'I a ,stay strip 28 is shown partially severed from the stay strip material to illustrate the preferred disposition of the fibers in a stay strip cut -i'rom the laminated sheet material shown in Figs. 'l and 8.

The characteristics of thestay strip material shown in Figs. 'I and 8 are generally similar to the characteristics of the stay strip material shown in Figs. 1 to-6. lThe stay strip material shown in Figs. 'I and 8 can, however, be made with a somewhat smoother surface than the stay strip materialshown in Figs..1 to 6.

In Fig. 9 an additional modification of this invention is shown for the purpose of further examplification of the practice of this invention. According to this embodiment of the invention a plurality of webs of unspim long fibers which are straightened and are arranged approximately in one direction are superposed so that the preponderant fiber directionof some of the webs is disposed at approximately a righi. angle to the preponderant fiber direction of other webs in the composite laminated sheet. In the embodiment shown the composite sheet, which is indicated generally by the reference character 3l, contains a total of eight laminations of the web material. In laminations 3|, l2, 3l, 35, 81 and 88 the preponderant ber direction is directly across the sheet 30 while in laminations 33 and 38 the preponderant ber direction is lengthwise of the sheet 80, and all of of these laminations the body of the sheet and intogether by binder material which is impregnated throughout the thickness substantially uni' are disposed similarly to webs 24 in a elements abutting each other.`

of the sheet 30 and is indicated in the drawing by the speckllng. An adhesive may be applied to the surface of the stay strip material as mentioned in connection with the other embodiments of this invention hereinabove described.

Stay strips may be cut from the sheet 30 along dotted lines 39, one such stay strip 40 being shown partially removed therefrom and being formed into a roll. In the resulting stay strip the bers are arranged so that the preponderant ber direction of part of the component webs is longitudinal of the stay strip and the preponderant ber direction of the other part of the component webs is directly across the stay strip. In the embodiment shown the preponderant ber direction of the major portion of the component webs is directly across the stay strip. 'Ihe structure shown therefore has maximum strength transverse of the stay strip and at the same time has substantial strength longitudinally of the stay strip. It is not necessary that laminations be disposed in the precise location shown 1n Fig. 9. Thus a greater or lesse;` proportion of webs with the preponderant ber direction longitudinally disposed in the stay strip or stay strip material can be used and a greater or lesser proportion of webs having the preponderant ber direction transversely disposed in the stay strip or stay strip material can be used. For example, the number of webs with the preponderant ber direction transverse the stay strip or composite sheet can be equal to the number of webs with the preponderant ber direction longitudinally of the stay strip or composite sheet, thus affording a composite sheet material and stay strip having approximately equal strength longitudinally and transversely. It is preferable however, that a major proportion of the webs be arranged with the ber direction across the stay strip. It is apparent that the strength characteristics of the stay strip can be varied in other ways according to the requirements of the use to which it is to be put in the practice of this invention.

The type of stay strip illustrated in Fig. 9 has less capacity to yield both longitudinally and laterally than do the stay strips shown in Figs. 1 to 4.

In the fabrication of the stay strip illustrated in the drawing and described hereinabove it is of great advantage to preliminarily form thin web material in which the bers are arranged preponderantly in one direction and preponderantly straight in said direction and then fabricate a composite sheet from the web material so as to provide in the sheet a plurality of webs of controlled ber orientation. The bers can be brought into straightened condition and into a uni-directional condition to higher degree when working with a thin web than when working with a thick mass of bers. Moreover, by building up the composite sheet from a relatively large number of thin superposed webs, the ber disposition in the composite sheet can be controlled to much better advantage. It is preferable to make up individual webs which weigh about 100 to 250 grains per square yard and While somewhat heavier webs can be used it becomes diicult to work with webs weighing more than about 400 grains per square yard. From another point of view the webs preferably contain about 2 to 8 bers in the thickness thereof. Sufficient webs of the thin diaphanous character mentioned are used to obtain in the nished composite sheet a weight of about 800 to 2200 grains per square yard. 'I'hls usually requires about 4 to 12 superposed laminations in preferred practice. In this manner ber disposition in the nished composite sheet can be controlled and at the same time bodies of bers having a preponderant ber direction are brought into integral superposed association with bodies of fibers having another preponderant ber direction so that bodiesof bers while different in direction are nevertheless integrated into a unitary laminated sheet having great strength and minimum tendency to separate into component layers.

In the fabrication of stay strip material it is preferable to employ bers that are about an inch or more in length. However, ber which contains a major proportion of fibers over 1/2 inch in length is to be regarded as long ber herein and may be advantageously used in the practice of this invention. A ber such as cotton ber which contains 60% or more of fibers over 1% inch in length may also be advantageously used. Preferably, however, the proportion of short bers, e. g., less than 1% or 1/2 inch, is less than about 30% of the bers. It is possible, of course, to reduce the proportion of short bers to 10% or less by combing or the like, but usually it is not necessary to go to the expense of removing the proportion of short bers that occurs in cotton o1 the like as ordinarily sold.

In the manner described in my application, Serial Number 349,311, led August 1, 1940, one can readily form web material for fabrication into stay strips, which web material contains a major proportion of fibers that have a preponderant ber direction and are approximately straight. By bonding the web material while it is under tension the bers disposed approximately in the direction of the tension can be bonded together in a condition of tensioned straightness. Thus, in the practice of this invention, it is preferable to employ web material in which at least about of the bers are disposed in a preponderant ber direction and are within about 15 of said preponderant ber direction. While some of the bers in the web, particularly the short bers, may be somewhat indiscriminately disposed, such bers merely act as a ller, and while the proportion of bers indiscriminately disposed in the web material can be reduced as by repeated drafting and lapping operations or by combing, it is not necessary to do so unless optimum strength characteristics for weight of ber is desired. When the web material is made as described in my application, Serial Number 349,311, led August 1, 1940, one can readily produce web material in which over 70% or 80% of the bers over 61 inch in length are disposed approximately in one direction, e. g., within about 15 of the preponderant ber direction, and the use of such web material, especially when such long bers are in a condition of tensioned straightness, constitutes preferred practice of this invention inasmuch as very high strength can thereby be attained in the stay strip material. Somewhat more generally any of the web materials described in my application above mentioned may be employed in the manufacture of stay strip material according to the present invention. While I regard it as preferable to make stay strips and stay strip material from web material fabricated as described in my application, Serial Number 349,311, led August 1, 1940, the present invention is not to be regarded as limited to employment of web materials thus made inasmuch as other web materials containing unspun fibers that have been arranged in a preponderant fiber direction by drafting, drawing, combing or the like, may be used.

It is advantageous in the fabrication of stay strips of the type shown in Figs. 1 to 4 that a multi-ply stay strip can be made using a single elongated web of unspun long staple fibers having preponderant fiber direction longitudinally of the web. It is desirable that '75% of each deposited layer of the web material be covered by a succeeding layer of the web material and in preferred practiceabout 85 to 90% is covered by a succeeding layer. In this construction it is to be noted that the laminations are disposed somewhat diagonally across the thickness of the stay strip material as is evident in Figs. 2, 4 and 5. The diagonal disposition of the laminations of web material minimizes any tendency for the laminations to separate. The operation involved in making stay strip material of this type may be performed continuously, rapidly and economically.

As mentioned above, it is preferable that the preponderant fiber direction of the webs be at a small angle with respect to a line directly across the stay strip or stay strip material, i. e., the transverse or cross dimension of the stay strip or stay strip material. While this angle is preferably relatively small, e. g., about 3 to 15, webs thus disposed or disposed at any angle less than 45 to a line directly across the stay strip or stay strip material are regarded as transversely disposed in the stay strip or stay strip material. Preferably a major proportion of webs are arranged so that the preponderant fiber direction of some webs are at an angle with respect to the preponderant fiber direction of other webs but so that the maximum difference in fiber direction is less than 45.

While reference has been made in the foregoing speciflc example of the practice of this invention to the employment of cotton fiber, other fibers may also be used such as jute, hemp, sisal, manila and the like. Moreover, a material such as Spanish moss can be used if preliminarily treated to arrange the strands thereof in a pre ponderant ber direction and to cause them for the most part to be straightened in the preponderant fiber direction.

In the foregoing example bituminous material, such as asphalt having a softening point of about 140 F. to about 175 F. has been mentioned as desirable especially when blended with a material such as coumarone resin or latex is adapted to impart increased adhesiveness to the bituminous material. Other similar materials such as pitches and coal tar residues can be used. Moreover, other thermoplastic binder materials can be used such as thermoplastic cellulose esters and ethers, e. g. cellulose acetate, cellulose nitrate, ethyl cellulose, benzyl cellulose, etc. Thermoplastic synthetic resinous materials may also be used, such as vinyl acetate, vinyl acetate-vinyl chloride copolymer and the like. When a thermoplastic binder material is used advantage can be taken of its capacity to become sticky and adhesive upon heating to utilize the binder material to bond the stay strip to an article. While the same thermoplastic material may be used both as an adhesive to bond the stay strip to an article and as the binder incorporated throughout the body of the stay st'rip, this is not necessarily the case.

It is not essential that the binder for the stay strip be a thermoplastic material. Thus the stay strip material may be bonded with a vegetable or animal adhesive such as casein (e. g. milk casein), soya bean protein, glue, starch dextrine or the like. Such adhesives can be applied in the form of an aqueous solution, an emulsion or the like, to preformed composite stay strip material but is preferably applied to the web material before it is fabricated into the composite sheet or during the fabrication of the composite sheet. When adhesives of this character are employed it is preferable to cause them to set so as to have increased resistance to moisture. This can be done in any suitable manner as by treating the stay strip material after the binder material has been incorporated therein or in the cornponent webs with a setting agent such as formaldehyde, tannic acid, alum or the like, e. g., in an aqueous solution. The binder and the setting agent can beapplied as a bath with which the stay strip material or web material is contacted or by means of applicating rollers carrying the binder material or setting agent over or between which the stay strip material or web material is passed. In general, any treatment that bonds the bers of the composite sheet together and bonds the web laminations together may be employed. It is preferred to bond the fibers in a condition of tensioned straightness in striated elemental webs, before the webs are made into a composite sheet of stay strip material. In such case the binder can be applied in a condition such that it can be activated to impart stickiness thereto to bond the webs together as a composite sheet and after the composite sheet material has been thus made the setting agent can be applied.

When a non-thermoplastic bonding means is employed a separate adhesive should be used to cause the stay strip to adhere to the surface of an article. This adhesive may be ordinary glue activatable by water. In such case it is preferable to fill the stay strip material with a waterresistant binder so that the stay strip material may be impervious or slowly impervious to moisture and so that the glue when applied will remain largely on the surface of the stay strip without excessive penetration and so that when the glue is subsequently activated with water the water carrying dissolved glue will not strike through the stay strip. It is preferable, however, in order to minimize difficulties such as these to use a thermoplastic adhesive, e. g., of the character above mentioned, even though a non-thermoplastic binder is used in the body of the stay strip material and it is also preferable for reasons mentioned hereinabove to employ a thermoplastic adhesive that is not soluble in, softened by, or deteriorated by, moisture or dampness.

Ordinarily the binder that is incorporated in the stay strip is less than 50% of the weight of the fiber in the composite stay strip material inasmuch as greater quantities of binder tend to make the stay strip material excessively stiff and boardy. Ordinarily only about 25% of binder material on the weight of the liber is incorporated in the body of the stay strip material. Notwithstanding such relatively small quantities of binder stay strip material weighing from about 800 to 1200 grains per square yard can be made which has a tensile strength as high as 10 pounds` per inch in at least one direction for each grains per square yard of fiber. In other words, stay strip material containing about 1200 grains of ber per square yard, for example, and containing less than 50% of binder incorporated 1n transversely' of a stay strip. Considerably greater strength per weight of fiber can also be attained in the practice of this invention. In conventional stay strip material the Weight of fiber usually runs about 1000 to 2000 grains per square yard in order to obtain strength required to meet the strains encountered in use. Such material has a tensile strength transversely of the stay strip of only about 2 pounds per 100 grains of fiber. According to the present invention the amount of fiber thatis required to withstand such strains can be very greatly reduced and therimproved stay strip material can be made by a method which from the production point of view is much more economical. v

While it is preferable to make stay strip and stay strip material made entirely of striated webs of long fibers, it is not essential to do so inasmuch as one or more plies or laminations of other materials such as coating films, thin sheets of paper or other fibrous material or the like may be included on one side or the other ofstay strip or stay strip material or interposed betweensuperposed laminations of striated webs of long unspun bers in stay strip or stay strip material or otherwise used in conjunction with one or more striated webs of long unspun fibers.

If desired a suitable dye, pigmentA or other coloring material can be incorporated with the stay strip or stay strip material. This can conveniently be done at the sam'e time that the binder is applied thereby eliminating a separate coloring or -tinting operation.

While this invention has been described in connection with certain specific embodiments thereof it is to be understood that this has been done merely for the purpose of exempliiication and that described embodiments may be varied without departing from the scope of the invention. Accordingly, the scope of the invention is to be governed by the language of the following claims construed in the light of the foregoing description of the invention.

I claim: I

1. A stay strip inthe form of a ribbon-like strip, said strip comprising a plurality of webs of unspun long fibers, the fibers of said webs be-' ing arranged in thin striated web form in a preponderant fiber direction and said webs being disposed in a plurality of superposed laminations with the preponderant fiber direction of fibers in different superposed webs angularly disposed and with the preponderant fiber direcof at least one of said Webs disposed transversely of the strip within 45 of a line extending directly across Vthe strip, said webs and the fibers of said webs being bonded together to form an integral composite stay strip.

2. A stay strip'in the form of a ribbon-like strip, said strip comprising a plurality of Webs of unspun long fibers the majority of"which are over inch in length and are disposed substantially straight and in one direction in thin striated Web form, the individual webs being in superposed juxtaposition with the major portion of the total amount of the fibers in all of said webs contained in webshaving the preponderant fiber direction thereof, transverse of the strip within 45 of a line extending directly across the strip and with the preponderant fiber direction in juxtaposed Webs angularly disposed,

vsaid webs and the fibers of said webs being bonded together to form an integral composite stay strip.

3. A stay strip in the form oi aV ribbon-like strip, said strip comprising a plurality of webs of unspun longv fibers, the fibers of said Webs being arranged in thin striated web form in a preponderant fiber direction and said webs being disposed in a plurality of superposed laminations with the preponderant fiber direction of fibers in different superposed webs angularly disposed and with the preponderant fiber direction in the webs containing a major portion of said fibers in the strip differing in direction by less than about 30 and disposed transversely of the strip within about 30 of a line extending directly across the strip, said Webs and the fibers of said webs being bonded together to form an integral composite stay strip.

4. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of webs of unspun long fibers the major proportion of the fibers in the individual webs being substantially of tensioned straightness and arranged approximately in one direction in thin striated web-like form, said webs being in superposed laminations with the preponderant fiber direction in different superposed webs angularly disposed and with the preponderant fiber direction of at least one of said Webs disposed transversely of the strip within 45 of a line extending directly across the strip, said webs and the fibers of said webs being bonded together to'form an integral composite stay strip.

5. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of Webs of unspun long fibers, -the fibers of said webs being arranged in thin striated web form in a preponderant fiber direction and said webs being in superposed juxtaposition with the preponder ant directionV of fibers in juxtaposed webs angularly disposed and with the preponderant fiber direction of at least one of said webs disposed transversely of the strip within 45 of a line extendingdirectly across the strip, lsaid webs and the fibers of said webs being bonded together to form an integral composite stay strip and said stay strip carrying on at least one surface thereof a thermoplastic adhesive activatable by heat to impart stickiness thereto to bond said stay strip to the surface of an article.

6. A stay vstrip according to claim 5 wherein the fibers at the inner portion of the stay strip are bonded by a thermoplastic binder having a higher softening point than the softening point of the thermoplastic adhesive for bonding the stay strip to the surface of an article. i

7. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of superposed Webs of unspun long fibers, the individual webs being of thin striated web-like form wherein the fiber weight is about 100 to about 400 f grains per square yard and a major proportion of the iibersare substantially straight and disposed approximately in one direction in individual webs, the major proportion of said unspun longr fibers contained in said stay strip being contained in webs wherein the preponderant fiber direction is transverse of said stay strip within about 30 of aliiieaextending directly across the stay strip, and said Webs and the fibers of said webs being bonded together to form an integral composite stay strip. f

8. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of webs of unspun fibers including 60% of fibers at least 3A inch in length, a major proportion of the fibers including at least 70% of the bers over 3/4 inch in length being substantially straight and arranged approximately in one direction in individual thin striated webs, subtsantially all of said fibers that extend transversely of the stay strip being in' webs disposed so as to have the preponderant fiber direction thereof on opposite sides of the cross-sectional dimension and within about 3 to 15 thereof, and said webs and said fibers being bonded together to form an integral composite stay strip.

9. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of webs of unspunlong cotton fibers, a major proportion of the fibers of each web being substantially straight and arranged in thin striated web form approximately in one direction and the major proportion of the total amount of fibers inV all of said webs being in webs the preponderant fiber rection of which is disposed transversely of said stay strip within 45l of a line extending directly across the strip, said webs and ilbers of said webs being integrally bonded together and the weight of fiber in each of said webs being about 100 to 400 grains per square yard and the total weight of the fiber in all of said webs being about 800 to about 2200 grains per square yard.

10. A stay strip according to claim 9 wherein the weight of any binder for said long unspun cotton fibers in said stay strip is not more than 50% of the weight of the said fiber of said stay .strip and said stay strip has a strength transvindividual webs being arranged verse of the stay strip of at least 30 pounds per inch.

11. A stay strip in the form of a ribbon-like strip, said strip comprising a plurality of superposed webs of unspun long fibers, the fibers in in thin striated web-like form with a major proportion of the fibers substantially straight and disposed in approximately one direction, the preponderant fiber direction of some of said webs being substantially directly across the stay strip and the preponderant ber direction of others of saidwebs being substantially parallel to the longitudinal axis of said stay strip, there being at least about four superposed webs at any one point and said webs and the bers of said webs being bonded together to form an integral composite stay strip.

12. A stay strip in the form of a ribbon-like strip, said stripcomprising a plurality of superposed webs of long fibers, the fibers in the individual webs being arranged in thin striated weblike form and in a preponderant fiber direction, said webs andthe fibers therein being bonded together in an integral composite stay-strip containing not over of binder material on the weight of the ber, said stay strip containing at least one web wherein the preponderant fiber direction is transverse of the stay strip within 45 of a line extending directly across the stay strip, and said stay strip having a tensileY strength transversely of the stay strip of at least 10 pounds per inch for each grains of fiber per square yard.

JOSEPH GOLDMAN.

CERTIFICATE OF` CORRECTION.

Patent No.' l2,51%851- ond column JOSEPH GOLDMAN.

printed specification correction as follows: Page 2, secpage LL, first column, line 58 for "examplification" read '--exemplification-w line 59, for "butuxninousl the ease 1n the' Patent office.'

(Seal) --bituminous--j and second column,

line 9, for "25" second occurrence, line 56, for "examplification' --exemplificationng and that the said Letters Patent should be read this correction `therein that the sane may conform. to the record of A. n. 191th.

Henry Van Arsdale, Acting Commissioner of Patents. 

